The present invention relates to a baling machine for forming cylindrical bales of crop.
Machines, towed by a tractor, for forming large cylindrical bales of hay (so called "round balers") are well-known. As the machine advances, the crop is removed from a windrow by a pick-up mechanism and delivered rearwardly to a baling chamber where it is rolled into a bale.
In one basic widely known form of such machines, the baling chamber is defined by runs of driven belts which move outwardly to enlarge the chamber to accommodate the bale as it grows in size. The hay is caused to roll round upon itself into a core and the core rotates about its horizontal axis and finally a completed bale is formed, the chamber being fed throughout with hay. The fully formed bale is tied with twine to maintain its shape and is discharged through a gate formed by a rear portion of the machine.
In our commonly assigned, co-pending U.S. patent application Ser. No. 020,417 filed Mar. 2, 1987 we have described and claimed a machine which enables bales produced in such a chamber to be wrapped with a surface wrap such as net to maintain their shape.
In commonly assigned U.S. Pat. No. 4,677,807 issued July 7, 1987, there is described a twine tie baler, as described above, which has a surface wrap mechanism so embodied therein that the automatic twine tie initiating portion of the twine tie mechanism is used to automatically initiate operation of the surface wrap mechanism in response to bale size and to apply a desired amount of surface wrap to the bale. This function of the patented device is desirable because it enables one to vary the amount of wrap applied in accordance with the size of the bale being wrapped and thus avoid wasting wrapping material. However, the mechanism for achieving this is rather complicated.
The present invention enables such wastage of wrap to be reduced or avoided by use of relatively uncomplicated wrapping material metering devices.